Method of producing moire patterns



Aug. l2 1941i. H. GROSS METHOD OF PRODUCING MOIR PATTERNS Filed Sept.16, 1939 ORNEY Patented ug. 12, 1941 UNITED rss Partnry OFFICE Thisinvention relates to the production of moire scratch patterns on textilefabrics and, in particular, to the production of such patterns onfabrics made from cellulose acetate fibres, commercially known ascelanese.

In the art of producing moire scratch patterns,` the fabric iscustomarily treated while in two layers, which are usually formed byfolding the material either longitudinally or transversely to form atwo-ply web `and passing the web through a scratching machine in which amoire pattern is scratched on the surface of the fabric. After passingthrough the scratching machine and after suitable conditioning, the webis passed between heated calender rolls which apply heat and pressure tocause the design to be reproduced upon the inner or abutting surfaces ofboth of the plies, the final result being a characteristic moire effectwherein the scratched pattern has a different lustre or sheen than theremainder of the fabric.

yIn carrying on this process, care must be taken to maintain the twolayers in absolute registration as to weave. This is commonlyaccomplishedby the use of a tracing machine in which the two layers areinspected and cleaned, that is, adjusted to remove the traces and matchthe weave. This tracing and cleaning involves considerable care andexpense and is particularly troublesome when treating fabrics whichrequire moistening prior to scratching, such, for example, as celluloseacetate fibres. In treating such fibres, the material must be moistened,scratched and dried before being calendered. It is usually necessary toroll the material between each of these steps, due to the differentlengths of time required therein. 'This rolling and re-rolling of thematerial renders the proper tracing and cleaning extremely diiiicult dueto the natural creepage of the layers, particularly when formed into alarge roll. It is accordingly an object of the present invention toprovide a novel and improved process in which these diniculties areavoided.

Another object is to provide a novel and improved process for producinga moir scratch pattern on cellulose acetate fabrics.

Another object is to provide a process in which the tracing and cleaningoperations are reduced to a minimum.

Another object is to provide a process in which the necessity formaintaining an exact registration between the weaves of the two plies inthe scratching machine is eliminated.

Another object is to provide a process of the type above indicated whichis adapted to treatment of large rolls of material.

Various other objects and advantages will be apparent as the nature ofthe invention is more fully disclosed.

Although the novel features which are believed to ce characeristic ofthis invention are pointed out more particularly in the claims appendedhereto, the invention itself may be better understood by referring tothe following description, taken in connection with the accompanyingdrawing, in which certain specific embodiments thereof have been setforth for purposes of illustration.

In the drawing,

Fig. l is a diagrammatic view representing certain steps of the presentprocess and Fig. '2 is a diagrammatic View representing a modificationof the moistening step.

Referring to the drawing more in detail, the material is indicated asreceived for treatment in the form of a roll l0 on which the materialhas been rolled in two layers, an upper layer Il and a lower layer I 2,to form a two-ply web.

The roll Ill may be formed in accordance with standard practice fromdyedV goods which have Ibeen received for treatment. These goods arecommonly received in the form of a single layer roll. The material maybe transferred from this single layer roll to a standard folding machinewhich is adapted to so fold the material that both ends are madeavailable. An end cloth may be sewed onto each of the ends of thematerial and the material is then passed in two layers through a tracerwhere it is inspected for matching of the weave. In the event that theweave of the two layers cannot be matched, the material is discarded asit will 'be unsuited for the subsequent process.

After passing through the tracer, the material is rolled into a doublelayer roll which constitutes the roll l0 of Fig. 1. In certaininstances, two or more pieces of material may be attached together toproduce a large roll and facilitate the further treatment.

The material from the roll I0 is now passed through a tank I4 containinga bath of water I5. The material may be held in this tank by suitablemeans, such as a roller I6. A suitable spray I1 may be positioned to wetthe upper surface of the top layer Il so as to ensure an even anduniform wetting of the material as it passes through the tank.

terial.

A tank M lhas been shown merely for purposes of illustration. 'Ihematerial may be wet in other ways, such as by a spray or by passingbetween wet belts or the like. Fig. 2 discloses an alternate method ofwetting the material,

l which comprises a steam box 20 through which the material is passedfrom the roll I over a plurality of rolls 2l in a position to becontacted by steam which may be injected through a series of nozzles 22,fed by a supply pipe 23.

' It is to be understood, of course, that the mechanical construction ofthe steam box may be varied as desired and that the present showing isonly intended to be diagrammatic. Y

In accordance with the present invention, the web, after being moistenedas above described either by passage through the tank I4 of Fig. 1 orthrough the steam box of Fig. 2, is passed between guide rollers 25,after which the layers are separated, the upper layer Il passing over anembossed pattern roll 26 and the lower layer l2` being held by idlerrolls28 out of contact with the pattern roll. A` scratch roll 29 havinga plurality of flexible blades 3) of the usual form is rotated in areverse' direction so as to scratch the moir pattern on the upper layeras it passes over the embossed pattern roll 26. The scratching machineis of standard construction and only so much thereof has been shownherein as is necessary lto an understanding of the present invention.After passing through the scratching machine, the layers I IV and I2 areagain united by means of guide rolls 32 and may be passed over a guideroll 33 and rolled on a rod 34 to form a roll 35. The material on theroll 35 is in the form of a two-ply web, one layer of which has beenscratched by the blades 30. It is also in a wet condition due to themoistening step above described. The roll 35 may now be stored for alength off time t0.V partially dry the same. They are preferably allowedto stand on end over night so as to remove aA suflicient amount of waterto prevent the Ydye from running in the drying box, to be described. Y

After being thus partially dried, the material is taken from 'the rolls35 andcis passed through a dryingbox of suitable construction in'which`the materialv is thoroughly dried. It is now passed through a tracer` inwhich it is` inspected and treated to remove traces and to clean thematerial, that is, to remove the linesV produced by lack of registrationbetween the weaves of the two layers. The material may. be, re-rolledbetween the drying and tracing steps. if' desired. The materia-l thustraced and cleaned isnow passed between heatedl calender rolls, whereinheat and pressureY is applied to bring out the moir design upon theabutting surfaces of both layers of ma- It is of course important thatthe cleaning and tracing operation be accurately carried out s o thatthe moire design will be properly reproduced on both layers.

After passage through the calender rolls, the two layers may beseparated and rolled into single layer rolls.,

In carrying onthe above process, it will be noted that only one layer isscratched to produce the moire pattern. Consequently, the necessity forexact registration between the two layers in the scratchingmachine isavoided. The preliminary'tracing is used-for the purpose of determiningwhether or not the weaves in the two materials are identical.Thereafter, the material may be rolled and rerolled a plurality of timesand no attempt need be made to match the material during this part ofthe process. After the material has been scratched and dried, however,it may then be passed through the tracer and cleaned and matched beforepassing to the calender` rolls. By thus simplifying the process, it hasbeen found that a more uniform moir pattern isobtained and that wastedue to improper treatment and improper matching is materially reduced.By this process it is possible to treat large rolls of material, such,for example, as 700 to 800 double yards. As distinguished from this, theroll was limited by creepage of the material of the two layers to amaximum size of not over about double yards when the material wastreated in accordance with prior processes which involved scratching ofboth layers.

While the invention has been shown particularly as applied to a`material of the cellulose acetate type,lwhich requires moistening ofthefibres prior to scratching, it is to be understood that it may also beapplied to the treatment of other fabric materials in which themoistening step may be omitted ifv desired. Certain specific terms havebeen used for convenience in referring to various details of` theinvention. It is to be understood, however, that these terms are to begiven as broad an interpretation as the art. will permit and that theinvention is only to be limited in accordance with the following claims.

What is claimed is:

1. The method of producing moir scratch patterns in fabrics,whichcomprises folding said fabric transversely into a two-layer web,scratching a moire pattern on one of said layers only, matching theweave of said layers and applying heat and pressure to the two layers soas to cause the design :to be reproduced upon the surfaces of bothofsaid layers.

2. The method of producing moir scratch patterns in fabrics, whichcomprises folding said fabric transversely into a two-layer web,scratching a moire' pattern on one of said layers only, combining thelayers to form a two-ply web, matching the weave in said web and passingthe same between heated calender rolls to apply heat and pressurethereto for causing the design to be reproduced upon the surfaces ofboth layers.

3.' The method of producing moir scratch patternsin fabrics, .whichcomprises folding two layers of said fabric transversely to form atwo-ply web, moistening said web, scratching a moir pattern on one ofsaid layers only while moist, drying saidweb, matchingthe weave in saidtwo layers,and'sub'jecting-said web t0 heat and pressure to cause thedesign to be reproduced. upon the surfaces of, both Aof-said layers.

4; The method of producing moir scratch patterns in fabrics made fromcellulose acetate bres which, comprises folding said fabric transverselyto form a two layer web, moistening said web, scra.tching a moirepattern on one of said layers only while moist, drying said web,matching the weave thereof and subjecting the web to heat and pressurefor causing thepattern to be reproduced von the surfaces of both oflsaid layers.

HERMAN GROSS.

